Antenna



FIG. 1 is a front elevation view of an antenna showing my new design;

FIG. 2 is a top perspective view thereof;

FIG. 3 is a side elevation view thereof;

FIG. 4 is an opposing side elevation view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a front elevation view thereof in use.

The broken lines in FIG. 6 illustrate environment only and form no part of the claimed design. 

CLAIM The ornamental design for an antenna, as shown and described. 